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Blackburn B-7
The Blackburn B-7 was a single-engine two/three-seat biplane built to a British Air Ministry specification for a general-purpose, multitasking aircraft. It first flew in 1934, but no contracts were issued and only one aircraft was completed. Development Air Ministry specification G.4/31 called 386 for an aircraft to replace the Westland Wapiti and Fairey Gordon. The task list was long: day and night light bombing, dive bombing, reconnaissance and army co-operation. The specification attracted interest across the British aircraft industry and eight manufacturers were immediately involved in preparing prototypes, three receiving contracts and the others going forward as private ventures. Blackburn only became involved when the Air Ministry extended the role list to include coastal defence and torpedo bombing, Blackburn's speciality. Their contender became known as the B-7 after the Class B marking it carried and lacking an old-style Blackburn-type number. It was built on the Shark production line and had much in common with it.Flight 2 May 1935 The Shark had introduced a new wing construction to Blackburn, each wing having two outward slanting (at about 45°, rather than vertical), slightly distorted N-type struts linked by a single strut from lower front to upper rear spars. As a result of this Warren girder structure, few bracing wires compared to past practice were needed. The wings were slightly staggered and swept and had the same span and much smaller lower wing as the Shark. Unlike the Shark the wings did not fold; another significant difference was that wing area was increased to enhance the load carrying performance by increasing the chord. The B-7 shared with the Shark the semi-monocoque aluminium-clad watertight fuselage first seen on the M.1/30A and the divided main undercarriage necessitated by the torpedo-dropping role. Accommodation, equipment and armament was similar to that of the Shark. They also shared the 700 hp (520 kW) Armstrong Siddeley Tiger IV engine. The B-7 first flew on 28 November 1934. Operational history The B-7 was flown to Martlesham Heath for competitive trials in May 1935 and completed in October that year. By now, the specification was four years old, requirements had changed and there was little official interest in the results and none of the nine manufacturers was awarded a contract. Shortly afterwards, the B-7 was scapped. Specifications (bomber) |met or eng?=eng |crew=2/3 |capacity= |length m=12.08 |length ft=35 |length in=4⅓ |span m=14.02 |span ft=46 |span in=0 |width m= |width ft= |width in= |height m=3.89 |height ft=12 |height in=9 |wing area sqm= |wing area sqft= |empty weight kg= |empty weight lb= |gross weight kg=3,187 |gross weight lb=7,027 |eng1 number=1 |eng1 type=Armstrong Siddeley Tiger IV 14-cylinder double-row radial |eng1 kw=520 |eng1 hp=700 |eng2 number= |eng2 type= |eng2 kw= |eng2 hp= |max speed kmh=257 |max speed mph=at 6,000 ft (1,830)160 |cruise speed kmh=160 |cruise speed mph=100 |stall speed kmh= |stall speed mph= |range km=870 |range miles=540 |endurance h= |endurance min= |ceiling m=6,100 |ceiling ft=20,000 |climb rate ms=6.1 |climb rate ftmin=1,200 |armament1=1 × forward firing 0.303 in (7.7 mm) Vickers machine gun |armament2=1 × ring mounted 0.303 in (7.7 mm) Lewis Gun |armament3= |armament4= |armament5= |armament6= }} References Notes Bibliography * * Category:British military aircraft 1930–1939 B-07 Category:Torpedo bombers